André
Marie Ampère

Physicist and
mathematician, b. 22 January, 1775, at Lyons, France; d. at
Marseilles, 10 June, 1836. His father was a prosperous and educated
merchant, his mother charitable and pious, while he himself combined
the traits of both. The mathematical bent of his mind showed itself
very early. Before he knew his letters and numbers he is said to
have performed complex arithmetical computations by means of pebbles
and beans. His childhood days were spent in the village of
Poleymieux-les-Mont-d'Or, near Lyons. His father began to teach him
Latin, but, on discovering the boy's thirst for mathematical
knowledge, he provided him with the necessary books. It was not long
before he had mastered the elements of his chosen study, so that his
father was obliged to take the boy of eleven to the library at
Lyons, where he asked for the works of Bernoulli and Euler. On being
informed that these books were written in Latin, and that he would
need a knowledge of the calculus, he resumed the study of the one
and applied himself to that of the other, and at the end of a few
weeks was able to take up the serious perusal of difficult treatises
on applied mathematics. During the revolution his father returned to
Lyons, in 1793, expecting to be safer in the city. After the siege,
however, he fell a victim and was executed. This death was a great
shock to the delicate, sensitive boy, who for more than a year was
in a state bordering on idiocy. From this he was suddenly aroused by
the reading of two works: J.J. Rousseau's "Letters on Botany"
and Horace's "Ode to Licinius", which led him to the
immediate study of plants and of the classic poets. In 1799 he
married Julie Carron, who lived only five years longer, leaving a
son who afterwards became a writer of great literary merit. Ampère
was obliged to teach in order to support himself and family. At
first he gave private lessons in Lyons; later, in 1801, he left his
wife and child to take the chair of physics at the Ecole Centrale in
Bourg. There he wrote the article that attracted the attention of
Lalande and Delambre: "Considérations sur la théorie
mathématique du jeu". In this he attacks and solves the
problem of showing that the chances of the gambler are always
against him. It is noted for its elegant and polished, though
simple, application of the calculus of probabilities. The favourable
appreciation of his work by men like Delambre resulted in his call
to Lyons and later, in 1805, to the Ecole Polytechnique at Paris,
where, in 1809, he rose to the position of Professor of Analysis,
and was made Chevalier of the Legion of Honour, and where his work
alternated between mathematics, physics, and metaphysics. He
published a number of articles on calculus, on curves, and other
purely mathematical topics, as well as on chemistry and light, and
even on zoölogy. Ampère's fame, however, rests on his
remarkable work in electro-dynamics. It was on 11 September, 1820,
that an academician, returning from Geneva, repeated before the
Academy the epoch-marking experiments of the Danish savant Oersted.
A wire through which an electric current passes was shown to deflect
a magnetic needle, causing it to place itself at right angles to the
direction of the current. The connexion between electricity an
magnetism was indicated by these experiments, and the foundation was
laid for the science of electro-magnetics. Only a week later, on the
18th of the same month, Ampère demonstrated before the
Academy another remarkable fact: the mutual attraction or repulsion
of two parallel wires carrying currents, according as the currents
are in the same or in opposite directions. This laid the foundation
of the science of electro-dynamics.

Ampère
continued his experiments, published the results in 1822, and,
finally, developed his "Mathematical Theory of the Phenomena of
Electro-dynamics" in 1830. In 1821 he suggested an electric
telegraph, using separate wires for every letter. His final work,
published after his death, was the ambitious "Essai sur la
philosophie des sciences, ou exposition analytique d'une
classification naturelle de toutes les connaissances humaines".
His predilection for philosophic, psychological, and metaphysical
speculation was very marked. His arduous task as teacher, together
with the engrossing functions of a government official--he was
Inspector-General of the University--prevented him from devoting
himself more to the work of the experimenter. He was a member of the
Institute of France, the Royal Societies of London and Edinburgh,
the Acadamies of Berlin, Stockholm, Brussels, and Lisbon, and other
scientific societies. In 1872 Madame Chevreux edited his "Journal
and Correspondence". In 1881 the Paris Conference of
Electricians honoured his memory by naming the practical unit of
electric current the ampère. His religious life is
interesting. He says that at eighteen years he found three
culminating points in his life, his First Communion, the reading of
Thomas's "Eulogy of Descartes", and the taking of the
Bastille. His marriage to the pious Julie Carron was secretly
performed by a priest, her family refusing to recognize the
competency of the "constitutional" clergyman; this fact
impressed him very deeply. On the day of his wife's death he wrote
two verses from the Psalms, and the prayer, "O Lord, God of
Mercy, unite me in Heaven with those whom you have permitted me to
love on earth". Serious doubts harassed him at times, and made
him very unhappy. Then he would take refuge in the reading of the
Bible and the Fathers of the Church. "Doubt", he says in a
letter to a friend, "is the greatest torment that a man suffers
on earth". His death took place at Marseilles, in his
fifty-second year.